Pressure-fan.



PATENTED MAR. 19, 1907.

J. KEITH.

PRESSURE FAN.

APPLICATION FILED JUNE 12.1906.

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M TH 3 NT OM Em T Yd u 2% M A JY B VWW \NlTNEsSEs No. 847,585. PATENTEDMAR. 19, 1907.

' J. KEITH.

PRESSURE FAN.

APPLICATION FILED JUNE 12.1906.

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\NVENTQR, JAM E5 KEPr BY Attornej UNITED STATES,

JAMES KEITH, OF LONDON, ENGLAND.

PRESSURE-FAN.

No. 847,585. Specification of Application filed June 12, 1906- SerialNo- 321,324.

To all iohom it may concern:

Be it known that I, JAMES KEITH, a subject of the King of the UnitedKingdom of Great Britain and Ireland, residing at Lonuseful lmprovementsin Pressure-Fans, of which the following is a specification.

This invention relates to pressure-fans ofthe ty e 'in which a largenumber of small curved blades are secured in addle-wheel fashion on arotating shaft and tted in a casing having a central eye or eyes for theairinlet and a tangential outlet.

The present improvement consists, primarily, in providing the bladeswith guardchecks or rings at each end and furnishing the fan-casing withcorres onding guardcheeks closely fittin those 0 the fan to preventbackflow of t e air drawn in at the central eyes by the action of theblades which direct the air through the oulet and also in providingmeans for perfectly balancing the wheeiiwhile driving it from one sideat high spee In the accompanying drawings, which illustrate theinvention, Figures 1 and 2 are vertical sections of the improved fan,taken at right angles to each other, Fig. 2 being drawn end of the shaftis secured centrally of the width of the casing the boss E of afan-wheel E, to which are secured in a manner shown, particularly atFigs. 3 and 4, a number of curved blades F, extending laterally to anequal distance on each side of the center of the wheel and terminatingon. each side in I I cheeks H, bolte don, England, have invented certainnew'and inlet-opening 'to obtain t ciency. Generally twenty bladesshould be PATENT OFFICE.

Letters Patent. Patented March 19, 1907.

uard-cheeks G, made in the form of rings,

inding together the blades and closely fitting into corresondinglyshaped guardd to and extending within and around the'fan-casingA, the construction being such as to leave on each side a re-' cess Sbetween the said guard-cheeks H and the internal walls of the case A.

The Wheel being run from its center on a long bearing protruding intothe fan-casing, it is not liable to oscillate or go ofi the trut whendriven at high speeds, and the guardcheeks G and H may closely fit intoeach other, so as to preclude back esca e of the air drawn into thecentral eyes by t e action of' the blades, which latter are slightlycurved inward at the running edges, so as to cut or scoop up theincoming air on each side.

The fan-blades are preferably made of the form illustrated, beingsuitably proportioned as regards depth and length relative to the fittedin the wheel, though the invention is not limited to that number.

. Having now described my invention, What I claim, and desire to secureby Letters Patent' of the United States, is

The improved pressure-fan, comprising,

in combination, a fan-casing having central )7 intake-eyes, and atangential-outlet, and

formed with annular guard-cheeks around said eyes, recesses being leftbetween said cheeks and the internal walls of the casmg, a

blade-wheel formed with cheeks fitting said.

first-mentioned cheeks, a bracket bolted to the casin and a shaft havinga bearing 1n said brac et and protruding into said casing and carryingthe blade-wheel.

name to this specification in the presence of two subscribing witnesses.

i JAMES KEITH.

Witnesses:

K ,l IlVALLAoE FAIRWEATHER, QJNo. ARMSTRONG, Junr.

In testimony whereof I have signed my

